Commit Graph

2072 Commits

Author SHA1 Message Date
NeilBrown
079fa166a2 md/raid1,10: Remove use-after-free bug in make_request.
A single request to RAID1 or RAID10 might result in multiple
requests if there are known bad blocks that need to be avoided.

To detect if we need to submit another write request we test:
 	if (sectors_handled < (bio->bi_size >> 9)) {

However this is after we call **_write_done() so the 'bio' no longer
belongs to us - the writes could have completed and the bio freed.

So move the **_write_done call until after the test against
bio->bi_size.

This addresses https://bugzilla.kernel.org/show_bug.cgi?id=41862

Reported-by: Bruno Wolff III <bruno@wolff.to>
Tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:23 +10:00
NeilBrown
19d5f834d6 md/raid10: unify handling of write completion.
A write can complete at two different places:
1/ when the last member-device write completes, through
   raid10_end_write_request
2/ in make_request() when we remove the initial bias from ->remaining.

These two should do exactly the same thing and the comment says they
do, but they don't.

So factor the correct code out into a function and call it in both
places.  This makes the code much more similar to RAID1.

The difference is only significant if there is an error, and they
usually take a while, so it is unlikely that there will be an error
already when make_request is completing, so this is unlikely to cause
real problems.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:17 +10:00
NeilBrown
43220aa0f2 md/raid5: fix a hang on device failure.
Waiting for a 'blocked' rdev to become unblocked in the raid5d thread
cannot work with internal metadata as it is the raid5d thread which
will clear the blocked flag.
This wasn't a problem in 3.0 and earlier as we only set the blocked
flag when external metadata was used then.
However we now set it always, so we need to be more careful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-31 12:49:14 +10:00
NeilBrown
7da64a0abc md: fix clearing of 'blocked' flag in the presence of bad blocks.
When the 'blocked' flag on a device is cleared while there are
unacknowledged bad blocks we must fail the device.  This is needed for
backwards compatability of the interface.

The code currently uses the wrong test for "unacknowledged bad blocks
exist".  Change it to the right test.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-30 16:20:17 +10:00
NeilBrown
1b6afa1758 md/linear: avoid corrupting structure while waiting for rcu_free to complete.
I don't know what I was thinking putting 'rcu' after a dynamically
sized array!  The array could still be in use when we call rcu_free()
(That is the point) so we mustn't corrupt it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:53 +10:00
Namhyung Kim
a5bf4df0c8 md: use REQ_NOIDLE flag in md_super_write()
Queue idling is used for the anticipation of immediate
sequencial I/O's but md_super_write() is a kind of one-
shot operation, coupled with md_super_wait(), so the
idling in this case will be just a waste of time.

Specifying REQ_NOIDLE prevents it. Instead of adding
the flag to submit_bio() directly, use pre-defined
macro WRITE_FLUSH_FUA.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:34 +10:00
NeilBrown
aeb9b21184 md: ensure changes to 'write-mostly' are reflected in metadata.
The 'write-mostly' flag can be changed through sysfs.
With 0.90 metadata, those changes are reflected in the metadata.
For 1.x metadata, they aren't.

So fix super_1_sync to record 'write-mostly' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:08 +10:00
NeilBrown
5ef56c8fec md: report failure if a 'set faulty' request doesn't.
Sometimes a device will refuse to be set faulty.  e.g. RAID1 will
never let the last working device become faulty.

So check if "md_error()" did manage to set the faulty flag and fail
with EBUSY if it didn't.

Resolves-Debian-Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601198
Reported-by: Mike Hommey <mh+reportbug@glandium.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:42:51 +10:00
Mike Snitzer
ed8b752bcc dm table: set flush capability based on underlying devices
DM has always advertised both REQ_FLUSH and REQ_FUA flush capabilities
regardless of whether or not a given DM device's underlying devices
also advertised a need for them.

Block's flush-merge changes from 2.6.39 have proven to be more costly
for DM devices.  Performance regressions have been reported even when
DM's underlying devices do not advertise that they have a write cache.

Fix the performance regressions by configuring a DM device's flushing
capabilities based on those of the underlying devices' capabilities.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:08 +01:00
Milan Broz
772ae5f54d dm crypt: optionally support discard requests
Add optional parameter field to dmcrypt table and support
"allow_discards" option.

Discard requests bypass crypt queue processing. Bio is simple remapped
to underlying device.

Note that discard will be never enabled by default because of security
consequences.  It is up to the administrator to enable it for encrypted
devices.

(Note that userspace cryptsetup does not understand new optional
parameters yet.  Support for this will come later.  Until then, you
should use 'dmsetup' to enable and disable this.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:08 +01:00
Jonathan Brassow
327372797c dm raid: add md raid1 support
Support the MD RAID1 personality through dm-raid.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
b12d437b73 dm raid: support metadata devices
Add the ability to parse and use metadata devices to dm-raid.  Although
not strictly required, without the metadata devices, many features of
RAID are unavailable.  They are used to store a superblock and bitmap.

The role, or position in the array, of each device must be recorded in
its superblock.  This is to help with fault handling, array reshaping,
and sanity checks.  RAID 4/5/6 devices must be loaded in a specific order:
in this way, the 'array_position' field helps validate the correctness
of the mapping when it is loaded.  It can be used during reshaping to
identify which devices are added/removed.  Fault handling is impossible
without this field.  For example, when a device fails it is recorded in
the superblock.  If this is a RAID1 device and the offending device is
removed from the array, there must be a way during subsequent array
assembly to determine that the failed device was the one removed.  This
is done by correlating the 'array_position' field and the bit-field
variable 'failed_devices'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
46bed2b5c1 dm raid: add write_mostly parameter
Add the write_mostly parameter to RAID1 dm-raid tables.

This allows the user to set the WriteMostly flag on a RAID1 device that
should normally be avoided for read I/O.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
c1084561bb dm raid: add region_size parameter
Allow the user to specify the region_size.

Ensures that the supplied value meets md's constraints, viz. the number of
regions does not exceed 2^21.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Mikulas Patocka
759dea204c dm ioctl: forbid multiple device specifiers
Exactly one of name, uuid or device must be specified when referencing
an existing device.  This removes the ambiguity (risking the wrong
device being updated) if two conflicting parameters were specified.
Previously one parameter got used and any others were ignored silently.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mikulas Patocka
ba2e19b0f4 dm ioctl: introduce __get_dev_cell
Move logic to find device based on major/minor number to a separate
function __get_dev_cell (similar to __get_uuid_cell and __get_name_cell).
This makes the function __find_device_hash_cell more straightforward.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mikulas Patocka
0ddf9644cc dm ioctl: fill in device parameters in more ioctls
Move parameter filling from find_device to __find_device_hash_cell.

This patch causes ioctls using __find_device_hash_cell
(DM_DEV_REMOVE_CMD, DM_DEV_SUSPEND_CMD - resume, DM_TABLE_CLEAR_CMD)
to return device parameters, bringing them into line with the other
ioctls.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mike Snitzer
a3998799fb dm flakey: add corrupt_bio_byte feature
Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a
specified position with a specified value during intervals when the device is
"down".

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mike Snitzer
b26f5e3d71 dm flakey: add drop_writes
Add 'drop_writes' option to drop writes silently while the
device is 'down'.  Reads are not touched.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
dfd068b01f dm flakey: support feature args
Add the ability to specify arbitrary feature flags when creating a
flakey target.  This code uses the same target argument helpers that
the multipath target does.

Also remove the superfluous 'dm-flakey' prefixes from the error messages,
as they already contain the prefix 'flakey'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
30e4171bfe dm flakey: use dm_target_offset and support discards
Use dm_target_offset() and support discards.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
498f0103ea dm table: share target argument parsing functions
Move multipath target argument parsing code into dm-table so other
targets can share it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mikulas Patocka
a6e50b409d dm snapshot: skip reading origin when overwriting complete chunk
If we write a full chunk in the snapshot, skip reading the origin device
because the whole chunk will be overwritten anyway.

This patch changes the snapshot write logic when a full chunk is written.
In this case:
  1. allocate the exception
  2. dispatch the bio (but don't report the bio completion to device mapper)
  3. write the exception record
  4. report bio completed

Callbacks must be done through the kcopyd thread, because callbacks must not
race with each other.  So we create two new functions:

  dm_kcopyd_prepare_callback: allocate a job structure and prepare the callback.
  (This function must not be called from interrupt context.)

  dm_kcopyd_do_callback: submit callback.
  (This function may be called from interrupt context.)

Performance test (on snapshots with 4k chunk size):
  without the patch:
    non-direct-io sequential write (dd):    17.7MB/s
    direct-io sequential write (dd):        20.9MB/s
    non-direct-io random write (mkfs.ext2): 0.44s

  with the patch:
    non-direct-io sequential write (dd):    26.5MB/s
    direct-io sequential write (dd):        33.2MB/s
    non-direct-io random write (mkfs.ext2): 0.27s

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mikulas Patocka
d5b9dd04bd dm: ignore merge_bvec for snapshots when safe
Add a new flag DMF_MERGE_IS_OPTIONAL to struct mapped_device to indicate
whether the device can accept bios larger than the size its merge
function returns.  When set, use this to send large bios to snapshots
which can split them if necessary.  Snapshot I/O may be significantly
fragmented and this approach seems to improve peformance.

Before the patch, dm_set_device_limits restricted bio size to page size
if the underlying device had a merge function and the target didn't
provide a merge function.  After the patch, dm_set_device_limits
restricts bio size to page size if the underlying device has a merge
function, doesn't have DMF_MERGE_IS_OPTIONAL flag and the target doesn't
provide a merge function.

The snapshot target can't provide a merge function because when the merge
function is called, it is impossible to determine where the bio will be
remapped.  Previously this led us to impose a 4k limit, which we can
now remove if the snapshot store is located on a device without a merge
function.  Together with another patch for optimizing full chunk writes,
it improves performance from 29MB/s to 40MB/s when writing to the
filesystem on snapshot store.

If the snapshot store is placed on a non-dm device with a merge function
(such as md-raid), device mapper still limits all bios to page size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mike Snitzer
0864901254 dm table: clean dm_get_device and move exports
There is no need for __table_get_device to be factored out.
Also move the exports to the end of their respective functions.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Alasdair G Kergon
3e8dbb7f39 dm raid: tidy includes
A dm target only needs to use include/linux dm headers.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Alasdair G Kergon
2ca4c92f58 dm ioctl: prevent empty message
Detect invalid empty messages in core dm instead of requiring every target to
check this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Jonathan Brassow
13c87583ea dm raid: cleanup parameter handling
Re-order the parameters so they are handled consistently in the same order
where defined, parsed and output.

Only include rebuild parameters in the STATUSTYPE_TABLE output if they were
supplied in the original table line.

Correct the parameter count when outputting rebuild: there are two words,
not one.

Use case-independent checks for keywords (as in other device-mapper targets).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Jonathan Brassow
a2d2b0345a dm snapshot: style cleanups
Coding style cleanups.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-08-02 12:32:03 +01:00
Mikulas Patocka
aa3f0794d2 dm snapshot: remove unused definitions
Remove a couple of unused #defines.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Mikulas Patocka
5bf45a3dcd dm kcopyd: remove nr_pages field from job structure
The nr_pages field in struct kcopyd_job is only used temporarily in
run_pages_job() to count the number of required pages.
We can use a local variable instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Mikulas Patocka
4622afb3f5 dm kcopyd: remove offset field from job structure
The offset field in struct kcopyd_job is always zero so remove it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Joe Perches
e29e65aacb dm: use vzalloc
Use vzalloc() instead of vmalloc()+memset().

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Kirill A. Shutemov
6c9b27ab08 dm log: userspace use list_move
Replace list_del() followed by list_add() with list_move().

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Akinobu Mita
c8f543e078 dm log: clean up bit little endian bitops
Using __test_and_{set,clear}_bit_le() with ignoring its return value
can be replaced with __{set,clear}_bit_le().

This also removes unnecessary casts.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mike Snitzer
936688d7eb dm table: fix discard support
Remove 'discards_supported' from the dm_table structure.  The same
information can be easily discovered from the table's target(s) in
dm_table_supports_discards().

Before this fix dm_table_supports_discards() would skip checking the
individual targets' 'discards_supported' flag if any one target in the
table didn't set num_discard_requests > 0.  Now the per-target
'discards_supported' flag is effective at insuring the final DM device
advertises discard support.  But, to be clear, targets that don't
support discards (!num_discard_requests) will not receive discard
requests.

Also DMWARN if a target sets 'discards_supported' override but forgets
to set 'num_discard_requests'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Alasdair G Kergon
283a8328ca dm: suppress endian warnings
Suppress sparse warnings about cpu_to_le32() by using __le32 types for
on-disk data etc.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Alasdair G Kergon
d15b774c29 dm: fix idr leak on module removal
Destroy _minor_idr when unloading the core dm module.  (Found by kmemleak.)

Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mikulas Patocka
bb91bc7bac dm io: flush cpu cache with vmapped io
For normal kernel pages, CPU cache is synchronized by the dma layer.
However, this is not done for pages allocated with vmalloc. If we do I/O
to/from vmallocated pages, we must synchronize CPU cache explicitly.

Prior to doing I/O on vmallocated page we must call
flush_kernel_vmap_range to flush dirty cache on the virtual address.
After finished read we must call invalidate_kernel_vmap_range to
invalidate cache on the virtual address, so that accesses to the virtual
address return newly read data and not stale data from CPU cache.

This patch fixes metadata corruption on dm-snapshots on PA-RISC and
possibly other architectures with caches indexed by virtual address.

Cc: stable <stable@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mike Snitzer
286f367dad dm mpath: fix potential NULL pointer in feature arg processing
Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2011-08-02 12:32:00 +01:00
Mikulas Patocka
762a80d9fc dm snapshot: flush disk cache when merging
This patch makes dm-snapshot flush disk cache when writing metadata for
merging snapshot.

Without cache flushing the disk may reorder metadata write and other
data writes and there is a possibility of data corruption in case of
power fault.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:00 +01:00
Linus Torvalds
6140333d36 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (75 commits)
  md/raid10: handle further errors during fix_read_error better.
  md/raid10: Handle read errors during recovery better.
  md/raid10: simplify read error handling during recovery.
  md/raid10: record bad blocks due to write errors during resync/recovery.
  md/raid10:  attempt to fix read errors during resync/check
  md/raid10:  Handle write errors by updating badblock log.
  md/raid10: clear bad-block record when write succeeds.
  md/raid10: avoid writing to known bad blocks on known bad drives.
  md/raid10 record bad blocks as needed during recovery.
  md/raid10: avoid reading known bad blocks during resync/recovery.
  md/raid10 - avoid reading from known bad blocks - part 3
  md/raid10: avoid reading from known bad blocks - part 2
  md/raid10: avoid reading from known bad blocks - part 1
  md/raid10: Split handle_read_error out from raid10d.
  md/raid10: simplify/reindent some loops.
  md/raid5: Clear bad blocks on successful write.
  md/raid5.  Don't write to known bad block on doubtful devices.
  md/raid5: write errors should be recorded as bad blocks if possible.
  md/raid5: use bad-block log to improve handling of uncorrectable read errors.
  md/raid5: avoid reading from known bad blocks.
  ...
2011-07-28 05:50:27 -07:00
NeilBrown
58c54fcca3 md/raid10: handle further errors during fix_read_error better.
If we find more read/write errors we should record a bad block before
failing the device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
5e5702898e md/raid10: Handle read errors during recovery better.
Currently when we get a read error during recovery, we simply abort
the recovery.

Instead, repeat the read in page-sized blocks.
On successful reads, write to the target.
On read errors, record a bad block on the destination,
and only if that fails do we abort the recovery.

As we now retry reads we need to know where we read from.  This was in
bi_sector but that can be changed during a read attempt.
So store the correct from_addr and to_addr in the r10_bio for later
access.


Signed-off-by: NeilBrown<neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
e684e41db3 md/raid10: simplify read error handling during recovery.
If a read error is detected during recovery the code currently
fails the read device.
This isn't really necessary.  recovery_request_write will signal
a write error to end_sync_write and it will record a write
error on the destination device which will record a bad block
there or kick it from the array.

So just remove this call to do md_error.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
1a0b7cd826 md/raid10: record bad blocks due to write errors during resync/recovery.
If we get a write error during resync/recovery don't fail the device
but instead record a bad block.  If that fails we can then fail the
device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
f84ee364dd md/raid10: attempt to fix read errors during resync/check
We already attempt to fix read errors found during normal IO
and a 'repair' process.
It is best to try to repair them at any time they are found,
so move a test so that during sync and check a read error will
be corrected by over-writing with good data.

If both (all) devices have known bad blocks in the sync section we
won't try to fix even though the bad blocks might not overlap.  That
should be considered later.

Also if we hit a read error during recovery we don't try to fix it.
It would only be possible to fix if there were at least three copies
of data, which is not very common with RAID10.  But it should still
be considered later.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
bd870a16c5 md/raid10: Handle write errors by updating badblock log.
When we get a write error (in the data area, not in metadata),
update the badblock log rather than failing the whole device.

As the write may well be many blocks, we trying writing each
block individually and only log the ones which fail.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
749c55e942 md/raid10: clear bad-block record when write succeeds.
If we succeed in writing to a block that was recorded as
being bad, we clear the bad-block record.

This requires some delayed handling as the bad-block-list update has
to happen in process-context.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
d4432c23be md/raid10: avoid writing to known bad blocks on known bad drives.
Writing to known bad blocks on drives that have seen a write error
is asking for trouble.  So try to avoid these blocks.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00